[WBP2] Bulk, Assembled Conductors, AC Loss

[WBP2-04] Mechanical Properties of DyBaCuO Bulk Materials with Different Dy211 Content Under Repeated Loading

*Akira Murakami¹, Mahiro Abe¹ (1. National Institute of Technology, Ichinoseki College (Japan))

Keywords:

DyBaCuO,Bulk Material,Mechanical Properties,Bending Test,Repeated Loading

Since superconducting bulk materials are subjected to electromagnetic force and thermal stress in the superconducting devices repeatedly, investigation of mechanical properties not only under static loading but also under repeated loading is important for practical application. However, the mechanical properties have been investigated under static loading mainly so far. In this study, in order to investigate the mechanical properties under repeated loading of DyBaCuO single-grain superconducting bulk materials with 15, 20 and 25 mol% Dy211, repeated bending load was applied to specimens cut from the bulk materials up to 10,000 cycles at the stress ratio of 0.1 and the frequency of 10 Hz. Specimens were fractured by the repeated loading, which is similar to metallic materials. On the other hand, different from metallic materials, number of cycles to the fracture of these DyBaCuO bulk materials did not increase with decreasing the stress amplitude. This implies that the fracture was largely affected by the existence of defects, such as pores, in the DyBaCuO bulk materials. Relationship between the mechanical properties and microstructures will be discussed.